Photoacoustic-guided surgery from head to toe [Invited]

Abstract

Photoacoustic imaging–the combination of optics and acoustics to visualize differences in optical absorption – has recently demonstrated strong viability as a promising method to provide critical guidance of multiple surgeries and procedures. Benefits include its potential to assist with tumor resection, identify hemorrhaged and ablated tissue, visualize metal implants (e.g., needle tips, tool tips, brachytherapy seeds), track catheter tips, and avoid accidental injury to critical subsurface anatomy (e.g., major vessels and nerves hidden by tissue during surgery). These benefits are significant because they reduce surgical error, associated surgery-related complications (e.g., cancer recurrence, paralysis, excessive bleeding), and accidental patient death in the operating room. This invited review covers multiple aspects of the use of photoacoustic imaging to guide both surgical and related non-surgical interventions. Applicable organ systems span structures within the head to contents of the toes, with an eye toward surgical and interventional translation for the benefit of patients and for use in operating rooms and interventional suites worldwide. We additionally include a critical discussion of complete systems and tools needed to maximize the success of surgical and interventional applications of photoacoustic-based technology, spanning light delivery, acoustic detection, and robotic methods. Multiple enabling hardware and software integration components are also discussed, concluding with a summary and future outlook based on the current state of technological developments, recent achievements, and possible new directions.

Acoustic Frequency-Based Approach for Identification of Photoacoustic Surgical Biomarkers

“…In clinical practice, we envision dual excitation wavelengths illuminating the region of interest with a fastswitching laser source that quickly alternates between wavelengths, providing real-time labeling of photoacousticsensitive regions with comparable performance to that achieved with more conventional spectral unmixing techniques. The proposed method could be beneficial for a range of emerging photoacoustic imaging approaches oriented to surgeries and interventions Wiacek and Lediju Bell, 2021), such as hysterectomies (Allard et al, 2018a;Allard et al, 2018b;Wiacek et al, 2019), neurosurgeries (Bell et al, 2014;Graham et al, 2019;Graham et al, 2020b;Graham et al, 2021), spinal fusion surgeries (Shubert and Lediju Bell, 2018;Gonzalez et al, 2019;, as well as identification and distinction of metallic tool tips (Eddins and Bell, 2017;Allard et al, 2018b), cardiac catheter tips (Graham et al, 2020a), and needle tips (Lediju from other surrounding structures of interest.…”

In vivo microscopy as an adjunctive tool to guide detection, diagnosis, and treatment

“…We draw our examples here from purely optical techniques that can serve in this complementary role, with a specific focus on imaging methods that offer cellular-level to subcellular-level resolution and depth-resolved imaging (i.e., optical sectioning). Though we do not address them in detail, there are many other promising in vivo imaging methods that are actively being investigated, including photoacoustic imaging, 17 – 19 optical coherence tomography (OCT), 20 and a variety of non-depth-resolved wide-field-microscopy approaches. 21 , 22 …”

Modeling combined ultrasound and photoacoustic imaging: Simulations aiding device development and artificial intelligence

“…The ease of integration of PAI capabilities to the clinical US systems further allowed the demonstration of dual-modality USPA devices capable of simultaneously displaying in real-time the anatomical and molecular information in pre-clinical as well as clinical research [ 4 , 5 ]. In recent years, many clinical applications of handheld USPA devices have emerged [ 6 , 7 ]; such as imaging of human breast [ [8] , [9] , [10] ], prostate [ 11 ], ovaries [ 12 ], muscular dystrophy [ 13 ], melanoma metastasis [ 14 ], inflammatory arthritis [ 15 ], thyroid [ 16 ], Crohn’s disease [ 17 ] and imaging human vasculature using portable LED arrays [ 18 ].…”